In U.S. Pat. Nos. 4,556,660; 4,634,704; 4,695,569; 4,695,575; 4,588,722; 4,835,161; 4,897,401 and in EPA-A-0,206,415 and 0,297,661 there are disclosed benzimidazole and imidazopyridine substituted piperidine derivatives as antihistaminics and serotonin antagonists.